In large-scale deployment and application of an IPTV (Internet Protocol TV) service, a problem of a low channel change speed becomes more and more prominent. To improve user experience, an FCC solution is used to accelerate a channel change process in the industry. An FCC server provides an FCC function for all users in its service scope. Different users may at the same time or at different times send FCC requests to the FCC server. When the same user rapidly selects a channel, the user may also send a plurality of FCC requests to the FCC server in a short time.
Picture in picture (Picture-in-Picture, PIP) uses a digital technology to display two programs on the same screen. That is, on a main picture that is being watched normally, one or more compressed sub-pictures are simultaneously inserted so that other channels are monitored when the main picture is watched. Picture in picture places a sub-picture in a main picture, and generally picture in picture is set for 4:3 color TV; picture off picture (Picture-off-Picture, POP) places a sub-picture outside a main picture, and generally picture off picture is set for 16:9 color TV. In a promotion advertisement, picture in picture and picture off picture are also generally called picture in picture.
The inventor discovers that a main picture and a sub-picture of picture in picture and picture off picture are different multicast groups and are sent to a terminal in a form of two separate multicast flows. In a current application, a main picture program has a large picture, a high definition, and a high channel rate, while a sub-picture has a small picture, a low definition, and a channel rate that is obviously lower than the rate of the main picture.
The inventor also notices that, a solution for the same user sending a plurality of FCC requests to an FCC server in a short time in the prior art is as follows: to satisfy that the same user performs consecutive multiple times of fast channel change, when the FCC server, in the case that the previous FCC of the same user is not completed, receives a new FCC request (also called a concurrent FCC request) is received, the FCC server starts a stop mechanism to end the previous FCC process.